I am not too concerned about whether an old canoe should be maintained in original condition. But, I think you neighbor's best bet for having a long-lasting result for his hard work in restoring the canoe would be to re-canvas.

Glass would only be on the outside, leaving the inside exposed to water (despite varnish). The result would be eventual delamination and then one hell of a nasty job trying to restore it again. The boat was engineered to be covered with canvas, the best result will be from doing it the way it was designed to be done.

: A neighbour is restoring his father's old cedarstrip/canvas canoe. He has
: removed the damaged canvas leaving flat ribs covered by thin (1/8" or
: less) 2.5" wide cedar strips. The strips are not tight to each other,
: but have approximately 1/16" gaps between them. Several of these
: strips are missing and will need to be replaced.

: He wants to eliminate the canvas and leave the outside as natural looking
: wood with the brass nail heads (attaching the cedar to the ribs) showing.
: His idea is to replace the missing cedar strips, leave the gaps and just
: fill them with epoxy/sawdust mixture, then glass the outside with one or
: two layers of 6 oz. fibreglass. There is not much strength with the very
: thin cedar, but he is hoping that by glassing the outside and using the
: ribs for strength, he can get away with just varnishing the inside, where
: the ribs prevent him from glassing. Any advice before he gets much
: further?

: John